Hi all, I’m trying to understand how to properly call an unknown function from low-level Cmm code. If I’m just applying a function to a state token, it’s easy; I can just do R1 = io; jump stg_ap_v_fast [R1]; since the calling convention is consistent in that case. But what if my function takes actual arguments? I can’t do R1 = fun; R2 = arg; jump stg_ap_p_fast [R1, R2]; because if the calling convention doesn’t pass any arguments in registers, that would be wrong. I could check if NO_ARG_REGS is defined and generate different code in that situation, but that seems extreme. One option I think would work would be to do R1 = fun; Sp_adj(-2); Sp(1) = arg; jump RET_LBL(stg_ap_p) [R1]; but that seems wasteful if I have the argument in a register already anyway. Am I missing something? Thanks, Alexis